- Create packages/highlight with shared Lezer-based syntax highlighting (types, parsers, highlighter, color maps)
- Add syntax highlighting and line numbers to file-pane.tsx with memoized CodeLine component
- Import shared highlight colors in git-diff-pane.tsx instead of local definitions
- Delete duplicated syntax-highlighter.ts from both app and server
- Fix TSX dialect to "ts jsx" (correct per Lezer docs)
- Move syntax highlighting from client to server for proper AST context
- Add highlighted_diff_request/response message types
- Create diff-highlighter and syntax-highlighter utils on server
- Fix TSX dialect to use "ts jsx" for proper TypeScript parsing
- Redesign diff UI: card-style file sections, GitHub Dark theme colors
- Reduce visual clutter: smaller padding, subtle backgrounds
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>